This invention generally relates to navigation or route guidance systems that can be tailored to a user's particular wishes.
Navigation systems generally provide a recommended route from a starting point to a desired destination. Generally the starting point and desired destination are selected from a large database of roads stored in a mass media storage, such as a CD ROM, which includes the roads in the area to be traveled by the user. The navigation system can be located in a personal computer or can be installed in a vehicle. If the navigation system is installed in a vehicle, the starting point is typically the current position of the vehicle, which can be input from an associated positioning determining device, such as a GPS (Global Positioning System) receiver.
The navigation system determines a route from the starting point to the destination utilizing an algorithm well-known to those in the art and currently in use in many navigation systems. Usually there are many potential routes between the selected starting point and the desired destination. The navigation system selects a recommended route based upon certain "cost" values associated with each segment of road in the road database. These cost values include the length of the road segment and the estimated time of travel through the road segment. The navigation system selects the potential route with the lowest total cost to be the recommended route. Depending upon the predetermined algorithm of the navigation system, the navigation system will recommend the route with the shortest total length, the lowest total time, or some weighted average of length and time.
The recommended route is then displayed to the user as a map showing the starting point and desired destination and highlighting the recommended route. Preferably, if the navigation system is installed in a vehicle, the navigation system displays the current position of the vehicle and turn-by-turn instructions to the driver, guiding the driver to the selected destination.
Some drivers prefer to avoid certain roads that they believe to be congested or certain areas that they believe to be unsafe. Some drivers may have a preference or aversion for particular types of roads such as highways or toll roads. Further, a route which is the shortest distance is sometimes preferred, while a route which is the lowest total time of travel is preferred at other times.
Current navigation systems have several limitations in how they select a potential route as the recommended route. The known navigation systems permit the driver to select one of the following preferences: fastest route; shortest route; use highways; avoid highways. However, the known systems do not permit the driver to adjust a weighting factor to be given to these preferences; nor can the driver adjust a balance between the fastest and shortest routes. Further, the known navigation systems do not permit the user to designate selected areas or roads to avoid or to adjust a preference/aversion factor of the road or area.